10891661 has 4 divisors (see below), whose sum is σ = 11881824. Its totient is φ = 9901500.

The previous prime is 10891649. The next prime is 10891663. The reversal of 10891661 is 16619801.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 10891661 - 2¹⁰ = 10890637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10891663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 495065 + ... + 495086.

It is an arithmetic number, because the mean of its divisors is an integer number (2970456).

Almost surely, 2^10891661 is an apocalyptic number.

10891661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10891661 is a deficient number, since it is larger than the sum of its proper divisors (990163).

10891661 is an equidigital number, since it uses as much as digits as its factorization.

10891661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990162.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 10891661 is about 3300.2516570710. The cubic root of 10891661 is about 221.6654661652.

The spelling of 10891661 in words is "ten million, eight hundred ninety-one thousand, six hundred sixty-one".